pressure treated wood for run

I am tearing apart an old deck and was considering reusing some of the boards for the garden or to build a run for my hens. I have heard warnings about pressure treated wood.
The wood is at least 12 years old. Would it be okay?
Let me know what you all think. I'm very hesitant about it, but these boards would be great.

New pressure treated boards can still be wet with the treatment and would definitely be a no no. But since these are weathered they should be okay as long as they haven't been weather treated with a water sealer in the recent past.

Thanks, estpr13.
They haven't been sealed for at least 12 years. I guess procrastination helped me out here!
It would be such a shame to dump them because they're nice sturdy long boards. I could never afford to buy something like that for my chicken run. I wouldn't hesitate to throw them if I was convinced they would be harmful though.

You can't compare new pressure treated wood with 12 year old wood when making your decision. In 2002/2003 the entire industry changed the chemical compostition of the solution the wood is treated with. Newer wood does not contain arsenic which is present in all PT wood made before then.

Looking at weathered wood isn't going to tell you how much arsenic is still present in the wood. A "wet" or "dry" appearance is meaningless. A study by the Envionmental Working Group has shown that the level of arsenic in the wood can remain at fairly high levels in 15 year old wood.

You don't say if the wood you wish to recycle will be in contact with the soil. This will speed up the leaching of arsenic into the soil much faster than if the wood is to be used above the soil.

Not to say that you shouldn't use the boards safely. Here's a recommendation from the Forest Products Lab about sealing old PT wood decks to increase safety for those concerned about exposure to the chemicals:

"To address this question, researchers at the Forest Products Lab (FPL) recently evaluated the ability of three common coatings to reduce leaching from CCA pressure treated wood. Replicate matched specimens of pressure treated 2 by 6 lumber were given one of the following coatings: (1) latex primer followed by one coat of outdoor latex paint, (2) oil-based primer followed by one coat of oil-based paint or (3) two coats of a penetrating oil semi-transparent deck stain. The specimens were then exposed to 30 inches of artificial rainfall for three weeks. The water running off the specimens was collected and analyzed for preservative components.

The results were very promising. All three coatings reduced leaching of arsenic pentoxide, chromium trioxide, and copper oxide by over 99% in comparison to uncoated specimens. None of the water collected from the specimens coated with latex or oil-based paint contained any detectable copper, chromium or arsenic. In some cases, water collected from the specimens that were coated with the penetrating oil stain did contain detectable levels, but the highest level of arsenic detected in these samples was still well below the EPAs drinking water standard. This study suggests that the application of these common coatings is an excellent recommendation for consumers who are worried about chemical exposure from CCA pressure treated wood. "

There is lots of information available on the web about the dangers of older pressure treated wood containing arsenic. You need to look at the sources though. A homeowner that tells you not to worry about it because his kids are playing on it every day and haven't died yet is not a reliable source. The EPA, I think underplayed the dangers a bit , not sure if environmental groups overstated them or not, but I think the wood industry did the correct thing in making a relatively speedy and voluntary transition. I feel a little better about including PT wood in home designs now.

On the other hand, if you design your run with hardware cloth on the inside, and sheathe the wood from the birds, you will probably be fine...we wanted treated wood for the uprights so the frame would last...and the birds don't get near it...

Just be sure the reclaimed wood is in good enough shape to re-use it...

Our current coop is under an upper story deck where a lower deck used to be. So the upright posts are pressure treated and the back wall (used to be the floor bottom of the lower deck) has been treated and painted. All of it is about 15 years old so probably not an issue at this point, but the chickens are not even interested in the wood. They have better things to peck at I guess. I like the strength it gives the run and it was cheap When I move the coop, I will probably incorporate some of this same wood into the new one.

Wow, lots to think about. Thanks everyone for your replies.
What I'm thinking now is to use the wood on the upright posts and the overhead beams. This should lesson breakdown of the wood and the release of the chemicals. I'll also seal it as Waynesgardens article indicated. I could wrap metal sheeting around the bottoms of the posts to keep the chickens from pecking on it.
Any more advice? Let me know if you think this won't help. I don't want to create a problem in my chicken area that would be in the soil forever.
Thanks so much!

I can't see how there would be a problem if you use the posts as uprights. If you sink them in concrete, and pull the concrete up above soil level as it should be, and stain them, you would have no leaching of chemicals into the soil. I have never seen my chickens peck a post! I would not use pressure treated wood for a roost as they have constant contact with that. If your chickens are pecking at posts, they have serious boredom issues!